FixVault

Diagnostic Procedure

NOTE: DO NOT  skip any steps in self-diagnostic tests or incorrect diagnosis may result.

Always perform a visual inspection before attempting to diagnose engine control system problems. See VISUAL INSPECTION  . Enter on-board diagnostics, and retrieve Diagnostic Trouble Codes (DTCs). See ENTERING ON-BOARD DIAGNOSTICS  . If DTCs are not present and/or scan tool is used, proceed to one of the following tests: